At 11:37 AM 11/14/04 -0500, Patrick Powers wrote: >Message text written by "John Carmichael" >>How many degrees should I incline the dial? Is there some set standard >that builders use for things like sidewalk drainage?<
>Be careful that they don't ask you to cone the surface of the dial or also >to provide a cross fall (that is drainage in all or two directions). The >delineation suffers. I just checked the engineering drawings for the Texas Instruments sundial, for which I was the astronomical consultant. The terrazzo base is 58 feet in diameter, and the gnomon rises obliquely from the exact center. The specs called for a conical slope of 5 percent, with drains around the periphery. Needless to say, the requirement for this subtle slope made the calculation of the hour lines "interesting." This large dial is located in the entrance court of TI's Forest Lane Facility outside Dallas, Texas. -- Roger -
